1. Field of Invention
The present invention relates generally to network devices. More particularly, the present invention relates to readily replacing failed protection circuitry in network devices that are used in constrained environments.
2. Description of the Related Art
T1 and E1 line interfaces on telecommunications (telecom) systems, e.g., twisted pair cable systems, are typically protected against voltage and current surges. Standards and regulations, including ITU K.20 and ITU K.21, generally require that line-interface portions of telecom systems include over voltage and over current protection. Circuit components which provide over voltage and over current protection are allowed to fail in a safe manner, and are permitted to be out of service. Once circuit components have failed, either the overall system that includes the circuit components, or an interface linecard that includes the circuit components, is typically returned to an appropriate manufacturer such that the circuit components may be replaced.
In addition to the inconvenience of having to return either an overall system or an interface linecard to a manufacturer for service in the event of a failure of circuit components, there may be instances in which the return of an overall system or an interface linecard is not possible. By way of example, an overall system may be used in a harsh or inaccessible field environment that renders either removing the overall system or opening the overall system to remove an interface linecard highly impractical or even impossible.
Therefore, what is needed is a method and an apparatus that allows protection circuitry associated with telecom systems to be efficiently replaced. That is, what is desired is a system which enables failed protection circuitry associated with a telecom device to be replaced without requiring that all or part of the device be removed from an environment in which the device is deployed.